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 ###Instrução: Quais são os números de série para as locomotivas da Classe 4-8-4 - oooooooo - northern?
 ###Tabelas: CREATE TABLE ner_associated_genes (ner_associated_genes_id AUTO_INCREMENT PRIMARY KEY, Human Gene (Protein) VARCHAR, Mouse Ortholog VARCHAR, Yeast Ortholog VARCHAR, Subpathway VARCHAR, GeneCards Entry VARCHAR) CREATE TABLE team_variations_across_different_versions (team_variations_across_different_versions_id AUTO_INCREMENT PRIMARY KEY, Gatchaman VARCHAR, Eagle Riders VARCHAR, Rank VARCHAR, Bird Uniform VARCHAR, Weapon VARCHAR, Mecha VARCHAR, Japanese voice actor VARCHAR, Voice actor (Eagle Riders) VARCHAR) CREATE TABLE energy_costs (energy_costs_id AUTO_INCREMENT PRIMARY KEY, 20 years VARCHAR, 2400 kWh/kW p y INT, 2200 kWh/kW p y INT, 2000 kWh/kW p y INT, 1800 kWh/kW p y INT, 1600 kWh/kW p y INT, 1400 kWh/kW p y INT, 1200 kWh/kW p y INT, 1000 kWh/kW p y INT, 800 kWh/kW p y INT) CREATE TABLE 4-8-4 (4-8-4_id AUTO_INCREMENT PRIMARY KEY, Class VARCHAR, Wheel arrangement VARCHAR, Fleet number(s) VARCHAR, Manufacturer VARCHAR, Serial numbers VARCHAR, Year made VARCHAR, Quantity made VARCHAR, Quantity preserved VARCHAR, Year(s) retired VARCHAR) CREATE TABLE chamber_of_deputies (chamber_of_deputies_id AUTO_INCREMENT PRIMARY KEY, Dist. INT, Democratic Coalition VARCHAR, Alliance VARCHAR, Together We Can Do More VARCHAR, Independent Regional Force VARCHAR, Independents VARCHAR)  
SELECT Serial numbers FROM 4-8-4 WHERE Class = 4-8-4 — oooooooo — northern